9949
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 31
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9950
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 9948
- Möbius Function
- -1
- Radical
- 9949
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 73
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1227
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- From the game of Mousetrap.at n=7A007710
- Number of ways of choosing at most n-1 items from a set of size 2*n+1.at n=7A008549
- a(n) = Sum_{k=0..6} binomial(n,k).at n=15A008859
- Primes that contain digits 4 and 9 only.at n=3A020466
- Triangle of numbers of permutations eliminating just k cards out of n in game of Mousetrap.at n=37A028305
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 90 ones.at n=0A031858
- Value of D for incrementally largest values of minimal x satisfying Pell equation x^2-Dy^2=1.at n=33A033316
- a(n) = 2^n - C(n,0) - C(n,1) - ... - C(n,8).at n=15A035041
- A convolution triangle of numbers, generalizing Pascal's triangle A007318.at n=29A035324
- Numbers having three 9's in base 10.at n=22A043527
- Primes whose digits are composite; primes having only {4, 6, 8, 9} as digits.at n=21A051416
- Primes having only 0,4,6,8,9 as digits.at n=33A061372
- Primes starting and ending with 9.at n=28A062335
- Numbers k such that 79^k - 78^k is prime.at n=6A062645
- The first of two consecutive primes with equal digital sums.at n=25A066540
- Numbers k such that prime(k+2)-(k+2)*tau(k+2) = prime(k-2)-(k-2)*tau(k-2) where tau(k) = A000005(k) is the number of divisors of k.at n=35A067354
- Minimal set of prime-strings in base 10.at n=19A071062
- Primes which are sandwiched between two numbers having the same unordered canonical form.at n=30A074460
- a(1) = 1 and then the smallest primes such that all a(k)-a(j) are distinct composite numbers.at n=43A079850
- Largest n-digit prime containing no prime substrings, or 0 if no such prime exists.at n=3A089771